FIELD OF THE INVENTION
[0001] The invention relates to communication technology, and in particular to a method
and system for performing edge to edge pseudo wire emulation of the bundling interface.
BACKGROUND OF THE INVENTION
[0002] The edge to edge pseudo wire emulation (PWE3) technology aims to connect the traditional
services, such as frame relay, Asynchronous Transfer Mode (ATM), and Ethernet, and
to provide service emulation over a packet switching network (PSN), thus realizing
the features of the emulated original services as much as possible. The technology
ensures the user service quality, and the user does not find any difference of the
services. During network construction and transition, the technology provides high
quality of interconnection between the user who is using the traditional services
and the operator, thus protecting the original investment of the user and the operator.
[0003] The link bundling technology is to bundle the physical interfaces, thus realizing
low cost and high bandwidth, for example, Ethernet bundling and Packet Over SDH (POS)
interface bundling. The link bundling technology usually includes two processes: establishing
a bundling interface, and adding a physical interface to the bundling interface as
a member interface. The bundling interface has the same physical attributes and three-layer
attributes as the independent physical interface. The bundling interface can run the
corresponding link layer protocols, such as address resolution protocol (ARP) of the
Ethernet, and high-speed data link control (HDLC) of the POS interface. The member
interface completes the one-to-one link protocol, and the status of the bundling interface
is maintained by the member interface status together.
[0004] In the Ethernet, the essence of the PWE3 technology is the point-to-point layer 2
virtual private network (VPN) technology. The link bundling process includes: first
establishing point-to-point pseudo wire (PW) between provider edge devices (PEs),
and then using label distribution protocol (LDP) or resource reservation protocol
(RSVP) to transmit the inner label between the two ends of the PW. The outer label
can be IP or label switch path (LSP). The outer label determines the PEs at the two
ends of the PW, and the inner label determines the specific PW on the PE. Meanwhile,
the physical features of the service are emulated over the forwarding layer, such
as the ATM Quality of Server (QoS) and the alarm indication of the synchronous digital
hierarchy (SDH). When the message is forwarded, the physical frame is directly encapsulated,
such as the cell of the ATM and the Ethernet frame, and the protocol carried by the
data frame is ignored, which applies to the point-to-point application.
[0005] The current internet engineering task force (IETF) draft has already defined the
encapsulation format of the Ethernet, ATM, frame relay, synchronous optical network
(SONET), and SDH emulation. But the draft can only apply to the PW establishment on
one interface and the message encapsulation.
[0006] Document XP015043178 describes that link aggregation can be used as Attachment Circuit
(AC) of the PWE3 service. Link aggregation is treated as a single interface. The member
interface of the Link Aggregation interface can be regarded as a sub-interface of
AC. A mechanism is needed to communicate the status of the member interface of the
Link Aggregation interface to the remote PE thus the 200Mb traffic may not be forwarded
to the PE.
[0007] Document XP015040861 describes a protocol for establishing and maintaining the pseudowires,
using extensions to Label Distribution Protocol (LDP). The PEs attempt to negotiate
the usage of the PW Status Type Length Value (TLV) when a PW is first set up. The
PW Status TLV will then be used for the lifetime of the Pseudowire. The interface
parameters sub-TLV specifies interface specific parameters. The interface parameters
sub-TLV type values are specified in "INTA Allocations for pseudo Wire Edge to Edge
Emulation (PWE3)".
[0008] Document
US 6 532 229 B1 describes a communication path selection method for sending a message between a sending
communication device and a receiving communication device in a communication network
includes a link aggregation group bitmap.
[0009] To implement PWE3 function on a router, the PW needs to be established according
to a specific physical interface. The interface bundling technology is a choice for
improving the physical bandwidth of the interface. The interface bundling has all
the attributes of the physical interface and meanwhile improves the bandwidth. To
the POS, the physical layer is the SDH and the link layer encapsulation is the point-to-point
protocol (PPP). Because a PWE3 is a point-to-point application, and ignores the link
protocol carried by the interface, the link layer needs to run the link aggregation
control protocol (LACP) to maintain the member physical interface status for the Ethernet
interface bundling on a one-to-one basis. For the member interface requiring one-to-one
link negotiation of the bundling interface, the link negotiation message of the member
interface is encapsulated by two-layer labels before reaching the remote end PE. Because
the inner label of the PE can only distinguish the PW, the inner label cannot distinguish
the corresponding member interface. The member interface cannot complete one-to-one
link path negotiation across the PSN. Therefore, the bundling interface requiring
negotiation between member interfaces cannot provide the PWE3 service.
SUMMARY OF THE INVENTION
[0010] The present invention is directed to implementing one-to-one link negotiation between
member interfaces across the PSN, thus realizing a method and system for performing
edge to edge pseudo wire emulation of the bundling interface.
[0011] The objective of this invention is realized through the following technical solutions:
[0012] A Provider Edge device (PE) for performing edge to edge pseudo wire emultion (PWE3)
of a bundling interface, comprising:
a bundling interface creating module adapted to create the bundling interface at the
PE and create a point-to-point pseudo wire, PW, on the bundling interface, wherein
the bundling interface comprises at least two member interfaces;
a sub-channel number assigning module adapted to assign a different sub-channel number
for each member interface of the bundling interface, thus differentiating different
member interfaces, wherein the sub-channel number of the member interface of the bundling
interface at two ends of the PW is one to one mapping;
a bundling parameter negotiating module adapted to negotiate bundling parameter to
realize one-to-one link negotiation of the member interfaces across a packet switching
network, PSN, wherein the bundling parameter comprises a bundling ability type indicating
whether the PE or its remote PE has bundling ability; and
a message forwarding module adapted to obtain a first sub-channel number of a first
member interface of the bundling interface, encapsulate the first sub-channel number
to a first Control Word, encapsulate a first message received from the first member
interface with the first Control Word, a first inner label and an outer label, and
forward the encapsulated message to the remote PE, wherein the first inner label determines
the PW and the outer label determines PEs at the two ends of the PW.
[0013] The bundling parameter negotiating module is adapted to distribute a label and to
negotiate the interface parameter employing a type-length-value (TLV) of label distribution
protocol (LDP).
[0014] Optionally, the message forwarding module is further adapted to obtain a corresponding
PW according to a second inner label encapsulated in a second message received from
the remote PE, obtain a second sub-channel number from a second Control Word encapsulated
in the second message, compare the second sub-channel number with its local sub-channel
numbers and forward the second message to a second member interface corresponding
to the second sub-channel number if the local sub-channel with the same sub-channel
number exists.
[0015] A system for performing edge to edge PWE3 of a bundling interface, comprises:
at least a peer of PE as described above.
[0016] A method for performing edge to edge pseudo wire emulation, PWE3, of a bundling interface,
comprising:
creating the bundling interface at a Provider Edge device,PE;
create a point-to-point pseudo wire, PW, on the bundling interface, wherein the bundling
interface comprises at least two member interfaces
assigning a sub-channel number to each member interface of the bundling interface,
wherein the sub-channel number of the member interface of the bundling interface at
two ends of the PW is one to one mapping;
negotiating bundling parameter to realize one-to-one link negotiation of the member
interfaces across a packet switching network, PSN, wherein the bundling parameter
comprises a bundling ability type indicating whether the PE or its remote PE has bundling
ability;
encapsulating a first sub-channel number of a first member interface of the bundling
interface into a first Control Word after receiving a first message from a Customer
Edge device, CE, through the first member interface;
encapsulating the first Control Word, a first inner label and an outer label into
the first message, wherein the first inner label determines the PW on the PE and the
outer label determines PEs at the two ends of the PW; and
sending the encapsulated message to the remote PE so that the remote PE transmits
the first message to a member interface of the bundling interface corresponding to
the first sub-channel number.
[0017] Optionally, the process of negotiating the bundling parameter comprises:
judging, by the PE, whether the PE receives a first LDP negotiation message from the
remote PE;
sending, by the PE, a second LDP negotiation message containing a second Control Word
to the remote PE and enabling a first bundling type length value, TLV, if the PE does
not receive the first LDP negotiation message;
judging whether the first negotiation message containing a third Control Word if the
PE receives the first LDP negotiation message;
judging whether a second bundling TLV is enabled if the first negotiation message
contains the third Control Word;
judging whether a local interface of the PE is a bundling interface according to local
attributes if the second TLV is enabled.
[0018] Optionally, the method further comprises:
obtaining a corresponding PW according to a second inner label;
obtaining a second sub-channel number from a second Control Word upon receiving a
second message from the remote PE through a second member interface of the bundling
interface; and
comparing the second sub-channel number with its local sub-channel numbers; and
sending the second message to its CE through a third member interface corresponding
to the second sub-channel number when a local sub-channel with the same sub-channel
number exists.
[0019] Optionally, the method further includes:
discarding, by the remote PE, the message when a local sub-channel with the same sub-channel
number does not exist.
[0020] The aforementioned technical solution provided by this invention shows that the invention
realizes one-to-one link path negotiation among the member interfaces of the bundling
interface through assigning sub-channel number to the member interface and by using
the LDP negotiation bundling parameter, thus ensuring the bundling link path feasibility.
This invention is easy to be implemented and has strong scalability.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021]
Figure 1 is a simplified diagram showing modules of a system according to an embodiment
of the present invention;
Figure 2 is a simplified schematic diagram showing the application of the PWE3 on
a bundling interface, in accordance with a particular embodiment;
Figure 3 is a simplified flowchart showing the operation process of a method according
to an embodiment of the present invention;
Figure 4 is a simplified flowchart showing the bundling parameter negotiation process
of a method according to an embodiment of the present invention; and
Figure 5 is a simplified flowchart showing a message forwarding process of a method
according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The invention is to provide a method and system for performing edge to edge pseudo
wire emulation of the bundling interface. The negotiation of the bundling ability
is completed through the LDP. The sub-channel number is assigned to the member interface
of the bundling interface, thus realizing one-to-one link negotiation of the member
interface across the PSN.
[0023] The invention provides a system for performing edge to edge pseudo wire emulation
of the bundling interface. In an embodiment, as shown in Figure 1, the PE side is
provided with, a bundling interface establishing module, a bundling parameter negotiating
module, a sub-channel number assigning module, and a message forwarding module. The
bundling interface establishing module is adapted to add at least two member interfaces
to a bundling interface on the PE, thus creating the bundling interface, and creating
a point-to-point PW on the bundling interface. The bundling parameter negotiating
module is adapted to negotiate whether two ends have a bundling ability. Figure 2
is a schematic diagram showing the application of the PWE3 on the bundling interface.
The LDP can be adapted to complete the assignment of the labels and the negotiation
of the interface parameter. For example, a Sub-TLV (TLV: Type Length Value) is employed
for the negotiation as follows:
[0024] The Type field on the bundling Sub-TLV is a bundling ability type, and the Length
field is 0.
[0025] The sub-channel number assigning module is adapted to assign a different sub-channel
number to each member interface of the bundling interface, thus differentiating different
member interfaces. The sub-channel number can be carried in the Control Word of the
PWE3. For example, the Ethernet interfaces bundling employs a format of the Control
Word as follows:
[0026] When b in the aforementioned Control Word is 1, it may indicate a sub-channel. The
sub cha-num indicates the sub-channel number, and the Reserved field is 0.
[0027] The following format of the Control Word is applied to a POS interfaces bundling:
[0028] When b in the aforementioned Control Word is 1, it may indicate a sub-channel. The
sub cha-num indicates the sub-channel number, and the Reserved field is 0.
[0029] The sub-channel number of a member interface of a bundling interface at two ends
of the PW is one-to-one mapping.
[0030] The message forwarding module is adapted to forward messages. When the PE sends messages
to a remote PE through a PSN, the message forwarding module encapsulates a sub-channel
number into the Control Word, forward the messages to a remote PE through a PSN; When
the PE sends messages to its CE, the message forwarding module takes out the sub-channel
number and compares the sub-channel number with its local sub-channel numbers, then
forwards the message to the corresponding member interface.
[0031] The invention provides a method for performing edge to edge pseudo wire emulation
of the bundling interface. As shown in Figure 3, the method includes the following
blocks:
[0032] Block 1: The LDP is configured to the PE side to be bundled. A bundling interface
is established at the two PEs and a point-to-point PW is created on the bundling interface.
[0033] Block 2: The PE adds a member interface to the bundling interface, and the sub-channel
number assigning module assigns a sub-channel number to each member interface. During
the assignment process, the sub-channel number of the member interface of the bundling
interface at the two ends of the PW is one-to-one mapping.
[0034] Block 3: The bundling parameter negotiating module uses the configured LDP to negotiate
the bundling parameter at the two ends.
[0035] The bundling parameter negotiating module can use the LDP, and use the Sub-TLV to
negotiate the bundling interface parameter. If one end does not support the bundling
ability, the PW cannot be established. The Control Word (C-Bit) in the mapping message
sent by the LDP two ends PW is equal to 1. As shown in Figure 4, the negotiation process
includes:
[0036] Block 30: When the PE is configured with the LDP, and is established with the bundling
interface PW, the PE judges whether it receives the LDP negotiation message from its
remote PE.
[0037] If the PE does not receive the LDP negotiation message, the PE sends the LDP negotiation
message to the remote PE and sets C-Bit=1, that is, the sent LDP negotiation message
contains the Control Word, and enables the bundling TLV.
[0038] Block 31: If the PE receives a negotiation message from the remote PE, the PE judges
whether C-Bit in the message is equal to 1, that is, the PE judges whether the negotiation
message contains the Control Word.
[0039] If the C-Bit is not equal to 1, the PE judges whether its local interface is the
bundling interface according to its local attributes. If yes, the PE sends a protocol-not-matched
message to the remote PE, indicating unsuccessful negotiation. If no, the PE assigns
labels locally and sends the labels to the remote PE through a label mapping message.
[0040] Block 32: If the C-Bit is 1, the PE judges whether the bundling TLV is enabled.
[0041] If not enabled, the PE assigns labels locally and sends the labels to the remote
PE through a label mapping message.
[0042] Block 33: If the bundling TLV is enabled, the PE judges whether its local interface
is a bundling interface according to its local attributes. If yes, the two ends PEs
can establish the bundling interface according to the current negotiation parameter.
If not, the PE sends error information to the remote PE.
[0043] The process of LDP negotiating bundling interface parameter is complete.
[0044] Block 4: The message forwarding module sends messages by using the aforementioned
bundling interface.
[0045] The forwarding plane receives a message from a member interface. Firstly, the message
forwarding module obtains the sub-channel number of the member, and encapsulates the
sub-channel number to a Control Word. Then the message received form the member interface
is encapsulated with the Control Word and two-layer labels. The encapsulated message
reaches the remote PE through the PSN. The message forwarding module of the remote
PE finds a corresponding PW through its inner label, obtains a sub-channel number
from the Control Word, and compares the sub-channel number with its local sub-channel
numbers. If the local sub-channel with the same sub-channel number exists, the module
sends a user message to the corresponding member interface, thus realizing one-to-one
link path negotiation of the bundling member. Figure 5 shows the specific operation
process, including:
[0046] Block 40: A port receives a message.
[0047] The message received by the port in this example includes: the PE receiving the message
from a customer edge device (CE) for encapsulation, and the PE sending the received
message from its remote PE to its CE.
[0048] Block 41: When the PE receives the message sent from the CE, it judges whether the
port enables the PW. If not enabled, the PE classifies the message according to the
type of the port.
[0049] Block 42: If enabled, the PE judges whether the port is a member interface of bundling
interface. If not, the PE encapsulates two-layer labels for forwarding.
[0050] Block 43: If the port is a member interface of bundling interface, the PE obtains
the sub-channel number, encapsulates the Control Word and the label, and forwards
the encapsulated message to the remote PE .
[0051] Block 44: When the PE receives the message to be sent to its CE, the PE judges whether
the message is a label message. If not, the PE queries the IP forward table to forward
the message.
[0052] Block 45: If the message is a label message, the PE judges whether the label is a
PW label. If not, the PE performs corresponding processes according to the label.
[0053] Block 46: If the label is a PW label, the PE obtains a sub-channel number from the
Control Word of the message, and compares the sub-channel number with its local sub-channel
numbers. If the local sub-channel with the same number exists, the PE transmits the
message to a member interface corresponding to the sub-channel number. If the sub-channel
does not exist, the PE discards the message.
[0054] In a word, this invention realizes one-to-one path negotiation of a bundling member
interface through assigning sub-channel number to the member interface and using the
LDP to negotiate the bundling parameter, thus ensuring the link bundling feasibility.
[0055] The above contents are better implementation modes of this invention, but the protection
scope of this invention is not limited to the contents. The change or replacement
that can be thought of by any technical personnel who are familiar with this technical
domain falls in the protection scope of this invention. Therefore, the protection
scope of this invention refers to that required by the rights.
1. A Provider Edge device, PE, for performing edge to edge pseudo wire emulation, PWE3,
of a bundling interface,
characterized by comprising:
a bundling interface creating module adapted to create the bundling interface at the
PE and create a point-to-point pseudo wire, PW, on the bundling interface, wherein
the bundling interface comprises at least two member interfaces;
a sub-channel number assigning module adapted to assign a different sub-channel number
for each member interface of the bundling interface, thus differentiating different
member interfaces, wherein the sub-channel number of the member interface of the bundling
interface at two ends of the PW is one to one mapping;
a bundling parameter negotiating module adapted to negotiate bundling parameter to
realize one-to-one link negotiation of the member interfaces across a packet switching
network, PSN, wherein the bundling parameter comprises a bundling ability type indicating
whether the PE or its remote PE has bundling ability; and
a message forwarding module adapted to obtain a first sub-channel number of a first
member interface of the bundling interface, encapsulate the first sub-channel number
to a first Control Word, encapsulate a first message received from a Customer Edge
device, CE, through the first member interface with the first Control Word, a first
inner label and an outer label, and forward the encapsulated message to the remote
PE, wherein the first inner label determines the PW and the outer label determines
PEs at the two ends of the PW.
2. The PE according to claim 1, wherein the bundling parameter negotiating module is
adapted to distribute a label and to negotiate the interface parameter by employing
a type-length-value, TLV, of label distribution protocol, LDP.
3. The PE according to claim 1, wherein the message forwarding module is further adapted
to obtain a corresponding PW according to a second inner label encapsulated in a second
message received from the remote PE, obtain a second sub-channel number from a second
Control Word encapsulated in the second message, compare the second sub-channel number
with its local sub-channel numbers and forward the second message to a second member
interface corresponding to the second sub-channel number if the local sub-channel
with the same sub-channel number exists.
4. A system for performing edge to edge pseudo wire emulation, PWE3, of a bundling interface,
comprising:
at least a peer of Provider Edge devices according to any one of claims 1-3.
5. A method for performing edge to edge pseudo wire emulation, PWE3, of a bundling interface,
characterized by comprising:
creating (1) the bundling interface at a Provider Edge device, PE;
creating (1) a point-to-point pseudo wire, PW, on the bundling interface, wherein
the bundling interface comprises at least two member interfaces
assigning (2) a sub-channel number to each member interface of the bundling interface,
wherein the sub-channel number of the member interface of the bundling interface at
two ends of the PW is one to one mapping;
negotiating (3) bundling parameter to realize one-to-one link negotiation of the member
interfaces across a packet switching network, PSN, wherein the bundling parameter
comprises a bundling ability type indicating whether the PE or its remote PE has bundling
ability;
encapsulating a first sub-channel number of a first member interface of the bundling
interface into a first Control Word after receiving a first message from a Customer
Edge device, CE, through the first member interface;
encapsulating the first Control Word, a first inner label and an outer label into
the first message, wherein the first inner label determines the PW on the PE and the
outer label determines PEs at the two ends of the PW; and
sending (4) the encapsulated message to the remote PE so that the remote PE transmits
the first message to a member interface of the bundling interface corresponding to
the first sub-channel number.
6. The method of claim 5, wherein the process of negotiating the bundling parameter comprises:
judging (30), by the PE, whether the PE receives a first LDP negotiation message from
the remote PE;
sending, by the PE, a second LDP negotiation message containing a second Control Word
to the remote PE and enabling a first bundling type length value, TLV, if the PE does
not receive the first LDP negotiation message;
judging (31) whether the first negotiation message containing a third Control Word
if the PE receives the first LDP negotiation message;
judging (32) whether a second bundling TLV is enabled if the first negotiation message
contains the third Control Word;
judging (33) whether a local interface of the PE is a bundling interface according
to local attributes if the second TLV is enabled.
7. The method of claim 5, further comprising;obtaining (45) a corresponding PW according
to a second inner label;
obtaining (46) a second sub-channel number from a second Control Word upon receiving
a second message from the remote PE through a second member interface of the bundling
interface; and
comparing the second sub-channel number with its local sub-channel numbers; and
sending (46) the second message to its CE through a third member interface corresponding
to the second sub-channel number when a local sub-channel with the same sub-channel
number exists.
8. The method according to claim 7, further comprising:
discarding, by the PE, the message when a local sub-channel with the same sub-channel
number does not exist.
1. Einrichtung der Provider Edge PE zum Durchführen von Pseudo-Wire-Emulation von Edge
zu Edge PWE3 einer Bündelungsschnittstelle,
dadurch gekennzeichnet, dass sie Folgendes umfasst:
ein Bündelungsschnittstellen-Erzeugungsmodul, das dafür ausgelegt ist, die Bündelungsschnittstelle
an der PE zu erzeugen und eine Pseudo-Wire PW von Punkt zu Punkt auf der Bündelungsschnittstelle
zu erzeugen, wobei die Bündelungsschnittstelle mindestens zwei zugehörige Schnittstellen
umfasst;
ein Subkanalnummern-Vergabemodul, das dafür ausgelegt ist, für jede zugehörige Schnittstelle
der Bündelungsschnittstelle eine andere Subkanalnummer zu vergeben und so verschiedene
zugehörige Schnittstellen zu differenzieren, wobei die Subkanalnummer der zugehörigen
Schnittstelle der Bündelungsschnittstelle an zwei Enden der PW eine injektive Abbildung
ist;
ein Bündelungsparameter-Aushandlungsmodul, das dafür ausgelegt ist, einen Bündelungsparameter
zur Realisierung von Aushandlung der injektiven Strecke der zugehörigen Schnittstellen
über ein Paketvermittlungsnetzwerk PSN hinweg auszuhandeln, wobei der Bündelungsparameter
einen Bündelungsfähigkeitstyp umfasst, der angibt, ob die PE oder ihre abgesetzte
PE Bündelungsfähigkeit aufweist; und
ein Nachrichtenweiterleitungsmodul, das dafür ausgelegt ist, eine erste Subkanalnummer
einer ersten zugehörigen Schnittstelle der Bündelungsschnittstelle zu erhalten, die
erste Subkanalnummer in ein erstes Steuerwort einzukapseln, eine von einer Einrichtung
der Customer Edge CE durch die erste zugehörige Schnittstelle empfangene erste Nachricht
mit dem ersten Steuerwort, einem ersten inneren Label und einem äußeren Label einzukapseln
und die eingekapselte Nachricht zu der abgesetzten PE weiterzuleiten, wobei das erste
innere Label die PW bestimmt und das äußere Label PE an den zwei Enden der PW bestimmt.
2. PE nach Anspruch 1, wobei das Bündelungsparameter-Aushandlungsmodul dafür ausgelegt
ist, ein Label zu verteilen und den Schnittstellenparameter durch Verwendung eines
Typ-Längenwerts TLV des Label-Verteilungsprotokolls LDP auszuhandeln.
3. PE nach Anspruch 1, wobei das Nachrichtenweiterleitungsmodul ferner dafür ausgelegt
ist, eine entsprechende PW gemäß einem in einer von der abgesetzten PE empfangenen
zweiten Nachricht eingekapselten zweiten inneren Label zu erhalten, eine zweite Subkanalnummer
von einem zweiten in die zweite Nachricht eingekapselten Steuerwort zu erhalten, die
zweite Subkanalnummer mit ihren lokalen Subkanalnummern zu vergleichen und die zweite
Nachricht zu einer zweiten zugehörigen Schnittstelle weiterzuleiten, die der zweiten
Subkanalnummer entspricht, wenn der lokale Subkanal mit derselben Subkanalnummer existiert.
4. System zum Durchführen von Pseudo-Wire-Emulation von Edge zu Edge PWE3 einer Bündelungsschnittstelle,
umfassend:
mindestens einen Peer von Einrichtungen der Provider Edge nach einem der Ansprüche
1-3.
5. Verfahren zum Durchführen von Pseudo-Wire-Emulation von Edge zu Edge PWE3 einer Bündelungsschnittstelle,
dadurch gekennzeichnet, dass es die folgenden Schritte umfasst:
Erzeugen (1) der Bündelungsschnittstelle in einer Einrichtung der Provider Edge PE;
Erzeugen (1) einer Pseudo-Wire PW von Punkt zu Punkt auf der Bündelungsschnittstelle,
wobei die Bündelungsschnittstelle mindestens zwei zugehörige Schnittstellen umfasst;
Vergeben (2) einer Subkanalnummer an jede zugehörige Schnittstelle der Bündelungsschnittstelle,
wobei die Subkanalnummer der zugehörigen Schnittstelle der Bündelungsschnittstelle
an zwei Enden der PW eine injektive Abbildung ist;
Aushandeln (3) eines Bündelungsparameters zur Realisierung von Aushandlung der injektiven
Strecke der zugehörigen Schnittstellen über ein Paketvermittlungsnetzwerk PSN hinweg,
wobei der Bündelungsparameter einen Bündelungsfähigkeitstyp umfasst, der angibt, ob
die PE oder ihre abgesetzte PE Bündelungsfähigkeit aufweist;
Einkapseln einer ersten Subkanalnummer einer ersten zugehörigen Schnittstelle der
Bündelungsschnittstelle in ein erstes Steuerwort nach dem Empfang einer ersten Nachricht
von einer Einrichtung der Customer Edge CE durch die erste zugehörige Schnittstelle;
Einkapseln des ersten Steuerworts, eines ersten inneren Labels und eines äußeren Labels
in die erste Nachricht, wobei das erste innere Label die PW auf der PE bestimmt und
das äußere Label PE an den zwei Enden der PW bestimmt; und
Senden (4) der eingekapselten Nachricht zu der abgesetzten PE, so dass die abgesetzte
PE die erste Nachricht zu einer zugehörigen Schnittstelle der Bündelungsschnittstelle
sendet, die der ersten Subkanalnummer entspricht.
6. Verfahren nach Anspruch 5, wobei der Prozess des Aushandelns des Bündelungsparameters
die folgenden Schritte umfasst:
Beurteilen (30) durch die PE, ob die PE eine erste LDP-Aushandlungsnachricht von der
abgesetzten PE empfängt;
Senden einer zweiten LDP-Aushandlungsnachricht, die ein zweites Steuerwort enthält,
durch die PE zu der abgesetzten PE und Freigeben eines ersten Bündelungstyp-Längenwerts
TLV, wenn die PE die erste LDP-Aushandlungsnachricht nicht empfängt;
Beurteilen (31), ob die erste Aushandlungsnachricht ein drittes Steuerwort enthält,
wenn die PE die erste LDP-Aushandlungsnachricht empfängt;
Beurteilen (32), ob ein zweiter Bündelungs-TLV freigegeben ist, wenn die erste Aushandlungsnachricht
das dritte Steuerwort enthält;
Beurteilen (33), ob eine lokale Schnittstelle der PE eine Bündelungsschnittstelle
ist, gemäß lokalen Attributen, wenn der zweite TLV freigegeben ist.
7. Verfahren nach Anspruch 5, ferner mit den folgenden Schritten:
Erhalten (45) einer entsprechenden PW gemäß einem zweiten inneren Label;
Erhalten (46) einer zweiten Subkanalnummer aus einem zweiten Steuerwort beim Empfang
einer zweiten Nachricht von der abgesetzten PE durch eine zweite zugehörige Schnittstelle
der Bündelungsschnittstelle; und
Vergleichen der zweiten Subkanalnummer mit ihren lokalen Subkanalnummern; und Senden
(46) der zweiten Nachricht zu ihrer CE durch eine dritte zugehörige Schnittstelle,
die der zweiten Subkanalnummer entspricht, wenn ein lokaler Subkanal mit derselben
Subkanalnummer existiert.
8. Verfahren nach Anspruch 7, ferner mit dem folgenden Schritt:
Verwerfen der Nachricht durch die PE, wenn kein lokaler Subkanal mit derselben Subkanalnummer
existiert.
1. Dispositif Périphérie Fournisseur, PE, pour effectuer une émulation de pseudo-fil
de bout en bout, PWE3, d'une interface de groupage,
caractérisé en ce qu'il comprend :
un module de création d'interface de groupage adapté pour créer l'interface de groupage
au niveau du PE et créer un pseudo-fil, PW, point à point, sur l'interface de groupage,
l'interface de groupage comprenant au moins deux interfaces membres ;
un module d'assignation de numéro de sous-canal adapté pour assigner un numéro de
sous-canal différent à chaque interface membre de l'interface de groupage, différenciant
ainsi différentes interfaces membres, le numéro de sous-canal de l'interface membre
de l'interface de groupage aux deux extrémités du PW correspondant à un mappage bi-univoque
;
un module de négociation de paramètre de groupage adapté pour négocier un paramètre
de groupage pour réaliser une négociation de liaison bi-univoque des interfaces membres
dans un réseau à commutation de paquets, PSN, le paramètre de groupage comprenant
un type de capacité de groupage indiquant si le PE ou son PE distant a une capacité
de groupage ou non ; et
un module de réacheminement de message adapté pour obtenir un premier numéro de sous-canal
d'une première interface membre de l'interface de groupage, encapsuler le premier
numéro de sous-canal dans un premier Mot de Commande, encapsuler un premier message
reçu d'un dispositif Périphérie Client, CE, par le biais de la première interface
membre avec le premier Mot de Commande, une première étiquette interne et une étiquette
externe, et réacheminer le message encapsulé vers le PE distant, la première étiquette
interne déterminant le PW et l'étiquette externe déterminant les PE aux deux extrémités
du PW.
2. PE selon la revendication 1, dans lequel le module de négociation de paramètre de
groupage est adapté pour distribuer une étiquette et négocier le paramètre d'interface
en employant une valeur de longueur de type, TLV, du protocole de distribution d'étiquettes,
LDP.
3. PE selon la revendication 1, dans lequel le module de réacheminement de message est
adapté en outre pour obtenir un PW correspondant en fonction d'une seconde étiquette
interne encapsulée dans un second message reçu du PE distant, obtenir un second numéro
de sous-canal à partir d'un second Mot de Commande encapsulé dans le second message,
comparer le second numéro de sous-canal à ses numéros de sous-canal locaux et réacheminer
le second message vers une deuxième interface membre correspondant au second numéro
de sous-canal si le sous-canal local ayant le même numéro de sous-canal existe.
4. Système d'exécution d'une émulation de pseudo-fil de bout en bout, PWE3, d'une interface
de groupage, comprenant :
au moins un homologue des dispositifs Périphérie Fournisseur selon l'une quelconque
des revendications 1 à 3.
5. Procédé d'exécution d'une émulation de pseudo-fil de bout en bout, PWE3, d'une interface
de groupage,
caractérisé en ce qu'il comprend :
la création (1) de l'interface de groupage au niveau d'un dispositif Périphérie Fournisseur,
PE ;
la création (1) d'un pseudo-fil, PW, point à point sur l'interface de groupage, l'interface
de groupage comprenant au moins deux interfaces membres ;
l'assignation (2) d'un numéro de sous-canal à chaque interface membre de l'interface
de groupage, le numéro de sous-canal de l'interface membre de l'interface de groupage
aux deux extrémités du PW correspondant à un mappage bi-univoque ;
la négociation (3) d'un paramètre de groupage pour réaliser une négociation de liaison
bi-univoque des interfaces membres dans un réseau à commutation de paquets, PSN, le
paramètre de groupage comprenant un type de capacité de groupage indiquant si le PE
ou son PE distant a une capacité de groupage ou non ;
l'encapsulage d'un premier numéro de sous-canal d'une première interface membre de
l'interface de groupage dans un premier Mot de Commande après la réception d'un premier
message en provenance d'un dispositif Périphérie Client, CE, par le biais de la première
interface membre ;
l'encapsulage du premier Mot de Commande, d'une première étiquette interne et d'une
étiquette externe dans le premier message, la première étiquette interne déterminant
le PW sur le PE et l'étiquette externe déterminant les PE aux deux extrémités du PW
; et
l'envoi (4) du message encapsulé au PE distant de telle sorte que le PE distant transmette
le premier message à une interface membre de l'interface de groupage correspondant
au premier numéro de sous-canal.
6. Procédé selon la revendication 5, dans lequel le processus de négociation du paramètre
de groupage comprend :
le jugement (30), par le PE, si le PE reçoit ou non un premier message de négociation
LDP du PE distant ;
l'envoi, par le PE, d'un second message de négociation LDP contenant un second Mot
de Commande au PE distant et la validation d'une première valeur de longueur de type
de groupage, TLV, si le PE ne reçoit pas le premier message de négociation LDP ;
le jugement (31) si le premier message de négociation contient ou non un troisième
Mot de Commande si le PE reçoit le premier message de négociation LDP ;
le jugement (32) si une seconde TLV de groupage est validée ou non si le premier message
de négociation contient le troisième Mot de Commande ;
le jugement (33) si une interface locale du PE est une interface de groupage ou non
en fonction d'attributs locaux si la seconde TLV est validée.
7. Procédé selon la revendication 5, comprenant en outre : l'obtention (45) d'un PW correspondant
en fonction d'une seconde étiquette interne ;
l'obtention (46) d'un second numéro de sous-canal à partir d'un second Mot de Commande
à la réception d'un second message provenant du PE distant par le biais d'une deuxième
interface membre de l'interface de groupage ; et
la comparaison du second numéro de sous-canal à ses numéros de sous-canal locaux ;
et
l'envoi (46) du second message à son CE par le biais d'une troisième interface membre
correspondant au second numéro de sous-canal quand un sous-canal local ayant le même
numéro de sous-canal existe.
8. Procédé selon la revendication 7, comprenant en outre :
le rejet, par le PE, du message quand il n'existe pas de sous-canal local ayant le
même numéro de sous-canal.